Loin knife blades for use with automatic loin puller apparatus

ABSTRACT

Dual loin knife blade members, in the form of a Z-blade and two styles (tabbed and non-tabbed) of J-blades, for use with knife assemblies in loin pulling machines for pork processing operations. The Z-blade knife comprises a shelf portion of extended length, formed of two separately-shaped blade portions, to maximize to the allowable customer dimensional length specification for the meat shelf being cut, while not cutting into and exposing the red meat of the pork loin eye. The J-blade, of either the tabbed or non-tabbed style, includes lower sweeping radius blade portions allowing the J-blade to lie closely adjacent and generally conform to the profile of the underlying split conveyor belt bed shape. The profiles for the present Z-blades and J-blades permit substantially increased yield in pork loin processing operations, reduced subsequent hand-trimming labor, as well as extended blade wear. A method is also disclosed for manufacturing the Z-blades and J-blades, resulting in increased wear, less surface drag on blade-related components and minimizing premature tab breakage on the tabbed-style J-blades.

TECHNICAL FIELD

This invention relates to knife blades used in the meat processingindustry, more particularly to knife blades used in loin knifeassemblies of automated loin puller apparatus to separate the loinportion from the belly and fatback portions in pork carcasses.

BACKGROUND

Automatic loin-pulling apparatuses have been developed over the yearsfor removing excess fat and also the belly loin area of an animalcarcass, i.e., as a step towards final cutting and packaging of theloin, belly, and fatback. Such automated loin pulling apparatusesinclude the devices disclosed in U.S. Pat. Nos. 6,089,968 and 6,547,658,for example, which disclose loin knife mechanisms for use withassociated meat carcass processing machines. Some such knife apparatusesutilize bent knife blades, including dual blade assemblies.

There is an ongoing high volume of meat carcasses, e.g., pork carcasses,being processed every work day. Thus, an improper knife blade placementmeasuring only 0.1 inch, for example, can cause drastic loss in yieldsand price reductions in the belly, loin, and fatback portions, orincrease further hand-trimming operations downstream. Thus, theindividual loin knives must be carefully shaped, and also able tocleanly cut in a smooth fashion. Further, such blade assemblies must beformed so as to withstand hundreds of thousands of cuttings, e.g.,10,000 cuttings per day or more for multiple months, before needingreplacement, so as to prevent costly downtime due to knife blademaintenance and/or change-out.

In the known dual blade loin knife assemblies of the prior art, see forexample U.S. Pat. No. 6,547,658, there are two kinds of blades. First,there are so-called “Z-blades”, operable to separate the loin portionfrom the belly portion of a hog carcass, as well as leave a so-called“belly shelf” and fingers of lean meat on the belly of a hog, forappearance and for superior bacon yields. Further, there are theso-called “J-blades,” which work from the chine or backbone side of thecarcass, used to separate the fatback portion from the loin portion.

However, due to the method of manufacturing such prior art blades,problems exist in the available normal cycles of usage of such blades,requiring relatively frequent machine downtime for blade replacement.Further, some meat processing machines necessitate that the J-bladeshave a so-called outwardly-extending “tab” portion, wherein an elongateddiverter bar member is held by the tab member, as used to direct andposition the trailing slab of fatback as it is cut from the porkcarcass. As to such prior art “tabbed”-style J-blades, it has been foundthat those tab portions often break prematurely next to their welds,i.e. before the normal life of the tabbed J-blade has been used up.

Further, the shapes used for the so-called “belly shelf” cuttingportions of the prior art Z-blades (as used for cutting a shelf throughthe longitudinal middle of the finger lean meat of the carcass) did notpermit the resultant cut belly shelf to reach the customers' maximumpermitted dimensional specification. Thus, unnecessarily large amountsof belly yield had to thereafter be removed off the loin portion, andthey became less-desirable trimmings (which are then worth substantiallyless). Further yet, the prior art style of “J-blades” have, due to theirspecific shapes, left unusually large portions of excess fatback on thepulled loin portion of the loin middle, and hence also provided poorfatback yields. That, in turn, necessitates extra effort down-the-linein hand trimming operations, resulting in both extra labor costs, aswell as a reduced amount of “good” (i.e. connected) fatback, i.e. whichis desirable due to the higher price received for sales of the trimmedfatback portion of the carcass when sold as one piece.

More specifically, meat processors using such dual blade loin knife-typemachines require that a satisfactorily “belly shelf” cut be made by theZ-blade, i.e. one that both falls within their dimensionalspecifications (typically some 2.5 inches±0.2 inches in length) andwhich also gets sufficient “fingers of lean” meat (found on the backside of the bacon, for good bacon yield), yet which blades also do notcut into or otherwise expose the loin eye meat (which would reduce thevalue of that select cut of meat). Further, most customers of the cutand pulled pork loins have a specification for their processors thatpermit no more than one-quarter inch of fat cover on the loin meat.Thus, there is a need to be able to trim the fatback over the loin asclose as possible to the loin eye meat, yet again without cutting intoand exposing the same.

Further, there has been an inability with the prior art types ofJ-blades to be adjusted sufficiently vertically, i.e. to be movedsubstantially down close to-the split conveyor belt bed relative to themeat carcass, due to their specific blade configuration. This inabilityto closely adjust to the bed profile created substantial yield loss forsuch prior J-blades. This was especially the case when such priorJ-blades where used in a meat processing plant which was runningso-called “European White” hogs, as those type of pork carcasses havevery little fat, and the red meat portions are located substantiallyclose to the skin. Thus, the prior J-blades were not of a shape thatcould be adjusted effectively relative to the conveyor belts, and thus,they could not run at desirable high yield rates, for processing such“European White” hogs.

Further yet, some processing customers require at the so-called“shoulder end” of the loin portion of the carcass, where some amount ofso-called “false lean” meat is present, that the majority of such falselean stay on the loin, yet they also want a small portion of such falselean to stay on the belly, so as to have sufficient meat in theremaining bacon portion.

Additional problems with the known prior art dual blades include thatthey are formed with relatively rough surfaces that create a substantialamount of cutting drag through the carcass. This in turn placessubstantial side loads on the loin puller machine's blade-relatedcomponents, such as the bushings, linkage parts, blade-holdingcomponents, and bearings. Thus, such blade-related components oftenrequire early replacement, necessitating machine downtime. Also, if suchworn components are not properly replaced, then due to the end-play thatthey create, there are yet additional yield losses, broken carcassbones, and improper meat cutting, resulting then in yet additional lostrevenue.

Thus, there has been a need for improved “Z-blades” and “J-blades” foruse in meat production operations, especially for use in pulling loinsin pork carcass processing plants.

SUMMARY

There is disclosed as one aspect of the present disclosure a Z-blademember having a cut belly shelf formed of an extended length, toconsistently reach the maximum end of the customer-set dimensionalspecification for that shelf. That shelf blade portion is formed of twodistinct sections, the first being a generally straight section adaptedto cut and divide the finger lean meat as close as possible to the sparerib around the pork middle, and a second further generally straightsection, but formed at a shallow angle canted down from the first shelfportion and adapted to operate as sufficiently low as needed to avoidcutting into any of the red meat portion of the loin eye, whether as asmall “pencil score” or as a large “body score”, in view of thesignificant extended length of that shelf portion of the Z-blade.

Another aspect of the present invention, as an alternate form, providesa Z-blade also having a shelf portion of extended length, again toregularly reach the customer's maximum belly shelf dimensionspecification, but formed of a gradual sweeping curve shape, rather thantwo straight sections divided by an intervening shallow angle. Again,the first part of the curve of the shelf is adapted to cut out thefinger lean meat close to the spare rib as possible, while the secondportion of the curve of the shelf is adapted to cut close to, yet staysufficiently distant from so as not to score, the loin eye meat.

Additionally, as another aspect of the disclosure, there is a J-blademember formed so as to have an initial meat cutting blade portion thatis substantially straight and formed at a tight upright angle, so as toclosely trim the “saddle area” of the fatback from adjacent the loinwithout over-exposing the false lean from the shoulder end or“over-scoring” the ham end (but still creating a desired “silverdollar”-size ham end score). Further, there is a lower sweeping curveportion, formed of a tight radius adapted to closely match the shape ofthe conveyor bed, so as to allow the blade to be adjusted closelyadjacent the same, thereby resulting in increased yield.

Another aspect of the disclosure is a modified form of the J-blade, foruse with machines that require a diverter bar tab member to be present,where the tab is so formed as to minimize its premature breakage beforethe blade is otherwise normally used up.

Further aspects of the disclosure include a method of forming Z-bladesand J-blades for a pork loin puller apparatus resulting in asubstantially extended useful life for such blades, a substantialelimination of the welded tab breakage problem of the prior art, andwith polishing of the blade surface, resulting in a substantialreduction in side loads on the blade-holders and other blade-relatedcomponents.

Yet a further aspect of the disclosure is a method for forming bothZ-blades and J-blades for meat carcass processing operations, where theresulting blades provide increased yields of loin, belly, and fatback,resulting in increased revenues, minimize hand-trimming operations, andhave a substantially increased overall useful life compared to prior artdual loin knife blades.

BRIEF DESCRIPTION OF THE DRAWINGS

The means by which the foregoing other aspects of the present inventionare accomplished, and the manner of their accomplishment will be readilyunderstood from the following specification upon reference to theaccompanying drawings, in which:

FIG. 1 is a front elevation view of a Z-blade of the present disclosure;

FIG. 2 is a side elevation view of the Z-blade of FIG. 1;

FIG. 3 is a cross-sectional view, taken along lines 3-3/44 of FIG. 1,reflecting a single bevel cutting edge, and shown as a right-hand blade;

FIG. 4 is a cross-sectional view, taken along lines 3-3/44 of FIG. 1,reflecting a single bevel cutting edge, and shown as a left-hand blade;

FIG. 5 is similar to FIGS. 3 and 4, but depicts a double bevel cuttingedge for a Z-blade;

FIG. 6 is a front elevation view of a J-blade of the present disclosure;

FIG. 7 is a side elevation view of the J-blade of FIG. 6 (configured asa left-hand blade,

FIG. 8 is a cross-sectional view, taken along lines 8-8/9-9 of FIG. 7,reflecting a single bevel cutting edge, and shown as a left-hand blade;

FIG. 9 is a cross-sectional view, taken along lines 8-8/9-9 of FIG. 7,reflecting a single bevel cutting edge, but shown as a right-hand blade;

FIG. 10 is similar to FIGS. 8 and 9, but depicts a double bevel cuttingedge for a J-blade;

FIG. 11 is a front elevation view of an alternate form of the J-blade,namely a tabbed-style J-blade;

FIG. 12 is a side elevation view of the tabbed-style J-blade of FIG. 11;

FIG. 13 is a cross-sectional view, taken along lines 13-13/14-14 of FIG.11, reflecting a single bevel cutting edge, and shown as a right-handblade;

FIG. 14 is a cross-sectional view, taken along lines 13-13/14-14 of FIG.11, reflecting a single bevel cutting edge, and shown as a left-handblade;

FIG. 15 is similar to FIGS. 13 and 14, but depicts a double bevelcutting edge for the tabbed-style J-blade;

FIG. 16 is an enlarged view of the Z-blade of FIG. 1, shown as aleft-handed blade in its operational environment above an associatedconveyor bed, and a loin meat carcass (shown at its shoulder end);

FIG. 17 is an enlarged view of the J-blade of FIG. 6, shown as aleft-handed blade in its operational environment above an associatedconveyor bed, and a loin meat carcass (shown at its shoulder end); and

FIG. 18 is an enlarged view of the alternate tabbed-type J-blade of FIG.11, shown as a left-handed blade in its operational environment with anassociated conveyor bed and a loin meat carcass (shown at its shoulderend).

DETAILED DESCRIPTION

The present disclosure relates to dual loin knife blades that provideimproved processing operating efficiencies and yields over the priorforms of Z-blades and J-blades as disclosed in U.S. Pat. No. 6,547,658,and further overcomes many of the deficiencies found in the blades, andtheir shapes and manufacturing methods.

Having reference to the drawings, wherein like reference numeralsindicate corresponding elements, there is shown in FIG. 1 anillustration of a Z-blade member, generally denoted by reference 20.Z-blade 20 includes (from top to bottom in that Figure): an uppermounting portion, generally denoted by region reference 22; an uppercentral blade portion 24; an angle bend forming a rib bone radiusportion 26; a shelf portion 28 comprising an upper initial or fingershelf portion 30, a relatively short shallow-angled shelf bend portion32, and a lower or loin eye avoidance shelf portion 34 (hereafter the“LAS portion”); an angle bend forming a belly cutoff radius 36; a bellycutoff blade portion 38; and a lower mount portion 40. Portions 28, 30,32, 34, 36 and 38, collectively, form a lower central blade portion.

More specifically, the upper mounting portion 22 of Z-blade 20 comprisesan S curve portion 42 and an upper mount portion 44 which mounts to aloin puller apparatus' upper blade mount (not shown). It will beunderstood that, depending on the specific mounting block arrangementand location (not shown) present in a given loin pulling machine (notshown), there may be a need for an even larger (or smaller) S curveportion, or instead, no need at all for the linkage-adjusting S curveportion 42 of Z-blade 20. Instead, portion 42 and upper mount portion 44can simply be formed as an elongated straight mounting section ofZ-blade 20, or even take some other configuration, again depending onthe specific upper mounting requirements for the Z-blade in a givenapplication.

As seen in FIGS. 1 and 2, the cutting edge 46 runs from an upper endpoint 48 to a lower end point 50. Those end points 48, 50 may be readilyextended upwardly and downwardly as needed for a given loin pullermachine, depending on the type and size (i.e. live weights) of hogcarcass being processed. Further, cutting edge 46 can be formed witheither an inner or outer single beveled cutting edge, such as shown inFIGS. 3 and 4, or instead, can be formed as a double bevel cutting edge,as shown in FIG. 5, depending on the preference of the customer. In FIG.2, cutting edge 46 is shown as an inner single bevel cutting edge (butagain, that type edge is depicted merely for purposes of presentation).

Upper central blade portion 24 is shown as a generally elongatedstraight section ending at its lower end in the rib bone radius 26. Itwill be understood that upper straight blade portion 24 is positionedsubstantially above the entry point of the meat carcass into the blade(such point being shown as line M-M in FIG. 2). Nevertheless, bladeportion 24 still carries a cutting edge 46, primarily so that if anycarcasses are improperly aligned within the loin pulling machine (notshown), the cutting edge 46 will be present to cut through the bones andmeat, so that such mis-aligned carcass section does not jam up themachine and cause unwanted downtime.

The angle of the rib bone radius 26 is quite tight, and thus, relativeto now the lower central blade portion, sets up an aggressivepositioning of the shelf portion 28 towards the loin area, as comparedto that angle in the known prior art blades, which instead typically hadmuch larger radii, such as 114°. That is, the angle of the present ribbone radius 26 is preferably in the range from approximately 107° to111°, and more preferably is approximately 109°.

The permitted length of a cut belly shelf on a loin is typicallyspecified by the end user customers to be 2.5 inches plus or minus 0.2inch. The prior art Z-blades, however, purposely had only a 2.5 inchmaximum shelf length. However, with the present invention, the shelflength (designated as length S.L. in FIG. 2) for the elongated shelfportion 28 is 2.7 inches, and therefore is able to cut deeper into thebelly area and near the loin eye meat. That resultant elongated lengthof cut belly shelf thereby increases the overall weight of the loinportion, with resultant increased revenues for the processors. However,if such an extended shelf length S.L. of 2.7 inches were undertaken witha straight shelf blade design, such as present in the known prior artZ-blades, that extended straight blade length would improperly cut rightinto the loin eye meat.

Advantageously, the present shelf 28 has been formed of two sections,namely an upper, initial finger shelf portion 30, which is formedpreferably as a straight section extending approximately 0.680 inch inlength, and within a preferred range from approximately 0.650 to 0.710inch in length, and then the second shelf or LAS section 34, i.e. theloin avoidance shelf portion, which is also formed preferably as astraight section having a length of approximately 0.561 inch, and withina preferred range from approximately 0.531 to 0.591 inch in length.Formed between those two shelf portions 30 and 34 is a bend angleportion 32 having a shallow bend angle a in the range of approximately9° to 13°, and preferably approximately 11.2°. The radius to createangle a is approximately 4.8845 to 4.9445 inches, and preferably 4.9145inches. Angle a allows the LAS blade portion 34 to cant down slightlyfrom the upper finger shelf portion 30. It will be understood that ifangle α is made too great, than the belly yield can be lost, i.e., thedepth of the edge of the belly is no larger as much as thecustomer-required depth specification of one-half inch minimum, therebynecessitating additional trimming labor to cut back the belly shelftowards the spare rib, until the required one-half inch depth dimensionis again attained. On the other hand, if angle α is made too small, thenthere is a risk of exposing and cutting into the loin eye meat by theLAS section 34. Thus, by using a bend angle a within the above range,for the extended shelf S.L., that angle a allows the LAS portion 34completely to avoid interference with the red meat of the loin eye.Thus, the two-part extended length shelf 28, with intervening angle a ofbend portion 32, is a substantial improvement over the straight shelvesof the prior art Z-blades, because an extended shelf length of meat cannow be cut, including cutting closer to the spare rib and through thefinger lean, yet without cutting into the loin eye meat. This extendedlength shelf results in substantial yield gains of the loin portions forthe meat processor.

As seen in FIG. 2, the cutoff radius 36 has a tight angle bend createdby a radius in the range from approximately 0.220 to 0.280 inches, andmore preferably of approximately 0.2500 inch. The angle between thelower shelf portion 34, relative to the belly cutoff blade portion 38,is formed within the range of approximately 117.2° and 121.8°, andpreferably approximately 119.5°. The belly cutoff blade portion 38 isthus formed as a substantially vertical portion including the cuttingedge 46 and lower end point 50, and is operable to cutoff the fatbackfrom the belly of the pork carcass. The lower mounting portion 40 mountswithin the lower mounting block (not shown) of the associated loinpulling machine (not shown); again, it can take any of several forms asneeded to be held properly by such mounting blocks. Thus, the shapeshown for lower mounting portion 40 in FIGS. 1 and 2 is merely forpurposes of illustration.

The overall length (designated as length O.L. in FIG. 2), for theZ-blade of the present disclosure is normally is the range fromapproximately 13⅞ inches to 14⅛ inches, and is preferably some 14 incheslong, as measured in its finally formed shape. The range of thicknessfor the Z-blade 20 is in the preferred range from approximately 0.130inches to 0.150 inches, and is preferably 0.140 inches. As noted, theupper central blade portion 24 and belly cutoff blade portion 38 aregenerally parallel to one another. As an alternate form of two sectionshelf 28, it could be formed as one continuous downwardly curvedsection, formed of a radius of preferably 7.287 inches, and within thepreferred range from 7.257 inches to 7.317 inches. Such a curved shelfblade portion of the extended 2.7 inch length is a substantialimprovement over prior art shelf blade portions.

Turning to FIGS. 6 and 7, there is shown as one aspect of the presentdisclosure, an improved J-blade, generally denoted by reference numeral60, and for use with certain types of loin puller machines. That is,certain loin puller apparatus (not shown) were modified into dual blademachines in the field, i.e. converted from a single hoop-style blademachine to a dual blade loin knife-type machine. Due to such fieldmodifications, including the style and location of the specific blademounting blocks used, and the other components found in those type loinpuller machines, the J-blades used with those field-modified machinesare necessarily formed of a specific shape. Thus, the improved J-blade60 for use with such field-modified machines includes a dual bevelcutting edge 62 (used for presentation purposes only in this disclosure,and again is dependent on the end user's preference), having respectiveupper and lower end points 64, 66. J-blade includes (from top to bottomin those Figures): an upper mount portion 68; an upper central bladeportion 70; a rib bone radius 72; a lower central blade portion havinggenerally straight fatback trimming portion 74, a transition area 76,and a sweeping radius portion 78; a cutoff angle bend 80; a generallystraight cutoff portion 82; and a lower blade mount portion 84.

More specifically, the upper central blade portion 70 comprises anS-curve portion 86 which helps properly position the upper mount portion68 in its needed linkage position. That is, the S-curve portion 86 helpsas a linkage step to properly locate (from left to right in FIG. 7) theupper mount portion 68 relative to the upper mounting block (not shown)of an associated field-modified loin puller machine (not shown). Thus,again here, similar to the above-described Z-blade, the blade portions68 and 70 can take other shapes rather than the S-curve portion 86, asneeded to accommodate the proper linkage positioning with the upperblade mounting blocks.

The feather bone radius 72 is preferably in the preferred range from0.220 to 0.280 inches, and more preferably is approximately 0.2500 inch.That relatively tight radius allows the straight fatback trim portion 74of the disclosed improved J-blade 60 to be aggressively positioned (i.e.in a fairly vertical alignment and quite close to, i.e. tighter intoagainst, the feather bones (not shown) of the pork carcass), than wasever previously available with the prior art J-blades. Preferably, therelative length of the straight fatback trim portion 74 is approximately2.079 inches long and within the preferred range of approximately 2.049to 2.109. Further, it will be understood that the prior art blades wereformed of a flat curve along that fatback trim portion of the overallJ-blade, rather than substantially straight as formed with the fatbacktrim portion 74 of the disclosed J-blade 60. By having such a straightblade portion for fatback trim portion 74, the result is that lessoverall fat remains on the loin portion that is pulled, and instead,more fat is cut into the fatback portion that is trimmed away. Thisresults in better yields, and hence, in better revenues for thoserespective sections of the carcass when sold.

There is a small transition area 76 located between the generallystraight fatback trim portion 74 and the sweeping radius portion 78 ofJ-blade 60. The radius for the sweeping radius portion 78 is much moreaggressive, i.e. is much tighter, than that present in the prior artJ-blades. That is, the radius in area 78 is preferably in the range fromapproximately 3.939 inches to 3.999 inches, and more preferably isapproximately 3.9691 inch. The sweeping radius portion 78 of J-blade 60operates to remove the fatback over the loin eye, and thus, that tightradius blade portion causes a smaller thickness of fat cover (not shown)to remain over the loin eye, yet that portion 78 does not enter the redmeat of the loin eye. For example, the most aggressive radius present inthe known prior art fatback blade portions was relatively flat, i.e.only approximately 4.117 inches, such that that relatively flat radiusinherently created a substantial yield loss in the fatback trim portionof the carcass. The tight sweeping radius of present blade portion 78then transitions into, and comes down low towards belt bed, due to thesharp cutoff angle bend 80. That sharp bend 80 has a preferred radius ofonly approximately 1.875 inch, and is within a preferred range of onlyapproximately 0.1575 inch to 0.2175 inch. The angle between the sweepingradius portion 78 relative to the cutoff portion 82, is formed withinthe range of approximately 83.9° and 88.5°, and preferably 86.2°.

Stated another way, the fatback trim portion 74 comprises approximatelythe first two fifths of the meat cutting portion of the J-blade 60, andthe lower sweeping radius portion 78 comprises approximately the lowerremaining three fifths. This aggressive shape, thus, trims the fatbackover the loin eye very close in with a tight radius, and puts the bladequite close to the red meat portion of the loin, resulting in a largerpiece of fatback that is now worth more, since it contains moreconnected weight. Further, the resulting loin is thus formed to be of avery first quality, since it has only the minimal dimensionalspecification of remaining fat cover. If the overall meat cuttingportions of the blade (i.e. portions 74 and 78) were formed too tight,i.e. too close in against the loin eye, then they would expose the loinred meat, which then drops the quality and price of the loin. On theother hand, if those blade portions 74, 78 were formed to be too looseor wide, then there is less fatback trimmed off, such that too much fatis left on the loin. That, in turn requires extra and costly subsequent“hand knife” labor for trimming away that, extra fatback. In effect, thetight radius of cutoff angle bend 80 allows the sweeping radius portion78 to start right away at its lower end, such that the sweeping radiusportion 78 gets up close into the loin eye area, and thereby, in effect,allows the greatest recovery of the fatback.

It will be noted that FIGS. 8, 9 and 10, disclose, respectively, innerand outer single bevel cutting edges 63, and a dual bevel cutting edge62.

Shown in FIGS. 11 and 12, as an alternate aspect of the presentdisclosure, is a modified form of a J-blade for use with those certaindifferent types of loin puller processing machines that need a tab forholding a diverter bar, and which machines are otherwise different fromthe machines which utilize the style of J-blade 60 of FIGS. 6 and 7.

Thus, there is shown in FIGS. 11 and 12, an improved tabbed-styleJ-blade, as generally denoted by reference numeral 90. Tabbed J-blade 90includes a dual bevel cutting edge 92 with respective upper and lowerend points 94, 96. The tabbed J-blade 90 includes (from top to bottom inFIG. 12): an upper mount portion 98; an upper central blade portion 100,which extends generally down to that point along tabbed blade 90 asdesignated by carcass entry line M-M, i.e. the line at approximatelywhich the top of the pork carcass enters the blade; an elongatedsweeping curve portion, generally designated by reference numeral 102,which includes two separate blade portions, namely a tight upper radiusor fatback trim portion 104, as separated by a transition area 106, anda tight lower radius or sweep radius portion 108 (which carries theintegrally-formed tab member 109, as having an inner opening 111 to holdand retain the associated diverter bar (not shown)); a cutoff angle bend110; a generally vertical cutoff blade portion 112; and finally, a lowermount portion 114.

More specifically, the upper central portion 100 includes a generallyshallow S-curve portion 116 which, along with the upper mount portion98, can be larger or smaller (as needed) and provides the properpositioning and linkage setup for mounting the upper end of the J-blade90 to the mounting blocks (not shown) of the loin puller machines (notshown). Again, as with the similar portion of the above-describedZ-blade 20 and J-blade 60, the upper portions 98 and 100 of tabbedJ-blade 90 can be formed in different configurations, as needed, to:accommodate the upper mounting block for a given loin puller machine(not shown). However, starting from essentially carcass entry line M-Mon down, the shapes of the various blade portions for tabbed J-blade 90are specially formed. The upper fatback trim portion 104 is preferablyformed of a radius in the range of approximately 3.970 inches to 4.030inches, and more preferably is of approximately 4.0 inches. This tightcurvature for upper fatback trim portion 104 permits the blade 90 atthat location to properly divide and trim the finger lean portions andto cut near the feather bone area of the loin, but without cutting intothe loin eye meat. Then, after the transition area 106, the separate anddifferent radius of the lower sweep radius portion 108 is within therange from approximately 3.470 inches to 3.530 inches, and morepreferably, is of approximately 3.5 inches. As seen, those tworespective and distinct radiuses blend into one another along thetransition area 106. The cutoff angle bend 110 is preferably formed of atight radius of approximately 0.360 inch, and within a preferred rangeof from 0.330 inch to 0.390 inch.

While it is of a slightly different overall shape from the correspondingportions of non-tabbed J-blade 60 (of FIGS. 6 an 7), the lower meatcutting portions 104 and 108 of the tabbed J-blade 90 are stillsubstantially more aggressive, i.e. tighter in towards the feather bonesand loin eye meat, than any of the known prior art tabbed-style J-bladedesigns. In effect, the curved cutting portions 104 and 108 permitsubstantially more fatback to be trimmed from the loin meat areas, andthus, add back an otherwise lost portion of the fatback segment, therebysubstantially increasing yields, over the prior art tabbed-styleJ-blade.

As shown in FIG. 16, the Z-blade 20 of the present disclosure isdepicted in its normal operating environment, namely in operation abovea split conveyor belt-type bed 116, as shown carrying the shoulder endof the pork loin, generally depicted by reference numeral 118. As seen,the shelf portion 28 properly cuts the finger lean meat 120 yet does notget too close to the loin meat 112. However, as will be understood, theZ-blade 20 is formed so as to leave a proper “silver dollar”-sized score(not shown) on the belly.

Turning to FIG. 17, there is shown, in the operating environment similarto FIG. 16, the non-tabbed J-blade 60 of the present disclosure,including the split conveyor belt bed 116 and the carcass shoulder end118. As seen, the sweeping radius portion 78 of non-tabbed J-blade 60mirrors, i.e. is shaped to closely follow, the overall profile of thebelt bed 116. Thus, when needed the blade, in effect, is allowed to laydown directly onto the belt bed, as it were, so as to be able to closelytrim the loin shoulder end 118. This blade profile-mirrors-bed profilefeature is particularly advantageous when pulling loins of so-called“European White” hog carcasses, yet can be accomplished without at allcutting into the belt bed 116. In effect, when blade 60 is so lowered,there is no “air gap” left between the profile of the lower sweepingradius portion 78 and the belt bed 116. This blade profile-mirrors-bedprofile feature is further accentuated by the fact that the radiusformed in cutoff angle bend 80 of non-tabbed J-blade 60 is substantiallysharp. Thus, a substantially greater amount of fatback 124 can be cutaway by the aggressive shape of the meat cutting portions of non-tabbedJ-blade 60. Further, the specific configuration of J-blade 60 will notover-expose false lean at the shoulder end or over-score the ham end ofthe loin.

Turning to FIG. 18, there is shown the tabbed J-blade 90 of the presentdisclosure as depicted in its operating environment (similar to FIGS. 16and 17), and again depicting the split conveyor belt bed 116 and theloin shoulder end 118. As noted, the angle of the cutoff angle bend 110is not quite as sharp, i.e. not as tight (as the corresponding angle ofcutoff angle bend 80 of non-tabbed J-blade 60). Nevertheless, the lowersweep radius portion 108 of tabbed J-blade 90 is still able to come downsubstantially close to, and have a generally similar profile to, theconveyor belt bed 116. Thus, here again, and contrary to the prior arttabbed J-blade designs, a substantial greater portion of the fatback 124of the carcass is able to be cut away from the loin 122 all so as to inincrease both loin and fatback yields when using the tabbed J-blade 90of the present disclosure. Further yet, the tabbed-style J-blade mustnot expose too much false lean, or “over score” the loin's ham end,i.e., beyond the desired “silver dollar”-size score.

Now, turning to the method of forming the various Z-blades and J-bladesof the present disclosure, it will be understood that the blades arepreferably formed of D-2 steel material, die-stamped rather thanhand-formed (as in the prior art) for greater accuracy and consistency,and are heat treated for greatest longevity. The preferred method forforming the respective blades of the present disclosure, thus, includesthe following steps:

(a) preliminarily, when forming a tabbed-style J-blade, form a lasercut, or mill cut as desired, of the profile of the blade and attachedtab, all as an integral unit formed from one piece of metal stock (suchthat the tab member is not a weaker piece due to being welded later onto a separate blade member, as was done in the prior art);

(b) mill the outer blade profile (either style of blade), on a millingmachine;

(c) machine the milled blades' overall cutting edge, whether as a doubleor single bevel edge, and whether as an inner or outer single beveledge;

(d) anneal the machined blades, so as to soften them, by subjecting themin a preferred temperature range of from approximately 1060° F. to1080°F., in the preferred time range from approximately 85-95 minutes;

(e) die-stamp the annealed blades, so as to form the actual accuratecurves, angle bends, and overall blade profile to the respective Z- andJ-blades;

(f) heat treat the die-stamped blades, to within the range on theRockwell scale of between approximately R.C. 44-54;

(g) quality control check the blade profile of the heat-treated blades,to make sure the cutting edge profile has not changed during the earlierheat treatment step; and

(h) polish all surfaces of the blades to generally a substantiallyflawless mirror-like finish, namely to a polished surface finish withinthe preferred range from approximately 4 to 32 microinches.

Thereafter, the finished and polished blades are wrapped and shipped tothe customer, whereupon the customer grinds on their own final cuttingedge, to their own specific edge grinding specifications and desires.They can also then subsequently re-sharpen the blade over its lifetimeof use.

Due to the foregoing method of forming the present Z- and J-blades, asubstantially superior blade member is obtained. For example, contraryto the rough surface finish established on the known prior art blades,the mirror-like polished surface finish found on the blades of thepresent disclosure helps to substantially reduce side load forcescreated by the blades as they cut through the meat carcasses. This isbecause the polished surface finish creates less drag on theblade-related machine components. This in turn substantially reducesblade wear, and blade-related component wear for the loin pullermachines, thereby resulting in increased savings in maintenance downtimeand replacement parts.

Further, the present tabbed-style J-blades are formed by laser cutting(or mill-cutting, as desired) both the blade and the tab as a singleunit, i.e. all formed as an integral piece from one piece of metalstock. This is contrary to the prior art method of welding and braisingon the tab as a separate item to the blade. Thus, due to thatdifference, the present one-piece tabbed-style J-blades has asubstantially longer useful life, as there is no problem in having awelded tab portion prematurely break off from the remaining bladeportion. Further, by heat treating the blades to be within the R.C.44-54 range, the present blades are substantially stronger and result ina longer useful life. Yet further, as a result of die-stamping thecurves and bends of the present Z- and J-blades, instead of hand formingthen as done with the prior art blade, a very accurate, andconsistently-formed, blade portion is achieved.

By permitting with the presently-disclosed blades an additional twotenths of an inch of fatback layer to remain on the belly (which aroundthe time of filing the subject application was running approximately$1.23 per pound, as contrasted to the then current price for fat handtrimmings off the loin of only $0.46 per pound), the extra two tenths ofan inch, across the entire length of the pork belly, times typicallysome 1200 carcass pieces per hour, times two loins per animal, times thetypical 16-hour per day shifts of such pork carcass processingoperations, results in additional revenue to the processor of literallytens of thousands of dollars per day. Similarly, substantial revenuesavings, in effect, occurs by reducing the amount of needed later “handtrimming” of excess fatback over the loin eye meat.

From the foregoing, it is believed that those skilled in the art willreadily appreciate the unique features and advantages of the presentdisclosure over the previous types of dual loin knife blades for meatprocessing operations. Further, the foregoing detailed description hasbeen given for clearness of understanding only, and no unnecessarylimitation should be understood therefrom, as modifications will beobvious to those skilled in the art.

1. A Z-blade apparatus for use in a dual blade loin knife assembly of aloin puller machine to create a loin portion, comprising: an elongatedblade member having distinct blade portions along its length including,in order, an upper mount portion adapted to mount to a blade mountingblock, an upper central portion normally not engaged to a meat carcassduring operation, a lower central portion normally engaged to a meatcarcass during operation, and a lower mount portion adapted to mount toa blade mounting block, at least the upper central and lower centralportions formed with a cutting edge, the lower central portion formed offurther portions including a shelf portion adapted to create a cut bellyshelf on the carcass, and a belly cut portion adapted to cut off thebelly, the shelf portion further comprising an upper shelf portionadapted to divide the finger lean meat and cut adjacent the featherbones, and a lower shelf portion adapted to cut closely adjacent, butnot into, the loin eye meat of the carcass, the shelf portion adapted toregularly cut a belly shelf on the carcass of approximately 2.7 inchesin length. The Z-blade apparatus of claim 1, and a radius portion formedbetween the upper central portion and the shelf portion.
 2. The Z-bladeapparatus of claim 1, and a radius portion formed between the uppercentral portion and the shelf portion.
 3. The Z-blade apparatus of claim1, wherein each of the upper and lower shelf portions are formed ofsubstantially straight blade portions separated by an angle bend.
 4. TheZ-blade apparatus of claim 3, wherein the angle of the angle bend iswithin the range of approximately 10° to 12°.
 5. The Z-blade apparatusof claim 3, wherein the substantially straight upper shelf portion has alength within the range of approximately 0.640 inch to 0.710 inch. 6.The Z-blade apparatus of claim 3, wherein the substantially straightlower shelf portion has a length within the range of approximately 0.531inch to 0.591 inch.
 7. The Z-blade apparatus of claim 1, wherein theupper and lower shelf portions are formed as a unitary curved bladeportion having an overall radius within the range of approximately 7.257inches to 7.317 inches.
 8. The Z-blade apparatus of claim 1, wherein theangle between the upper shelf portion, relative to the upper centralblade portion, is formed within the range of approximately 107° to 111°.9. The Z-blade apparatus of claim 1, wherein the angle between the lowershelf portion, relative to the belly cut portion, is formed of a radiuswithin the range of approximately 0.220 inch to 0.280 inch.
 10. TheZ-blade apparatus of claim 1, wherein the angle between the lower shelfportion, relative to the belly cut portion, is formed within the rangeof approximately 117.2° and 121.8°.
 11. The Z-blade apparatus of claim1, wherein the cutting edge is formed to be one of double-bevelled andsingle-bevelled.
 12. The Z-blade apparatus of claim 1, wherein therespective upper central portion and the belly cutoff sections aresubstantially straight blade portions.
 13. The Z-blade apparatus ofclaim 11, wherein the substantially straight upper central and bellycutoff portions are formed generally parallel to one another.
 14. TheZ-blade apparatus of claim 1, wherein the upper mount portion and theupper central portion are formed as an aligned continuous portion. 15.The Z-blade apparatus of claim 1, and wherein an S-curved portionseparates the upper mount portion from the upper central portion, tothereby create sufficient lateral positioning to accommodate properaligned mounting of the Z-blade apparatus to a given blade mountingblock.
 16. The Z-blade apparatus of claim 1, and wherein the length andangle of the lower shelf portion are so formed, relative to the bellycutoff central portion, to cut the meat carcass so as to consistentlyleave a cut loin portion bearing a fat cover layer of approximately onequarter inch.
 17. The Z-blade apparatus of claim 1, wherein theelongated blade member is formed of steel having a finished Rockwellhardness within the range of substantially between R.C. 44 to
 54. 18.The Z-blade apparatus of claim 16, and wherein the surface ofsubstantially the entire blade is polished, to a surface finishsmoothness within the range substantially between 4 and 32 microinches,so as to minimize surface drag on the Z-blade and wear on the relatedblade-holding components, as the Z-blade cuts through the meat carcass.19. The Z-blade apparatus of claim 1, wherein the lengths of therespective upper and lower shelf portions are substantially equal.
 20. AJ-blade apparatus for use in a dual blade loin knife assembly of a loinpuller machine to create a pulled loin portion, comprising: an elongatedblade member having different purpose blade portions along its lengthincluding, in order, an upper mount portion adapted to mount to a blademounting block, an upper central portion normally not engaged to a meatcarcass during operation, a lower central portion normally engaged to ameat carcass during operation, a cutoff portion, and a lower mountportion adapted to mount to a blade mounting block, at least the uppercentral and lower central portions having a cutting edge, the lowercentral portion formed of further portions including a fatback trimmingportion and a sweeping radius portion, the radius for the sweepingradius portion being no greater than approximately 3.999 inch.
 21. TheJ-blade apparatus of claim 19, and a feather bone radius portion formedbetween the upper central portion and lower central portion, the radiusfor the rib bone radius portion being no greater than approximately0.280 inch.
 22. The J-blade apparatus of claim 19, wherein the radius ofthe sweeping radius portion is formed to substantially match the radiusof the underlying conveyor belt bed of the associated loin pullermachine, whereby the sweeping radius portion can be adjusted downwardlyas close as needed to the conveyor belt bed to thereby,achieve maximum,cutting efficiencies for the loin puller machine.
 23. The J-bladeapparatus of claim 19, wherein the fatback trimming portion is formed asa generally straight blade portion.
 24. The J-blade apparatus of claim19, wherein the fatback trimming portion is formed as a curved bladeportion having a radius within the range of approximately 3.970 inchesto 4.030 inches.
 25. The J-blade apparatus of claim 23, wherein thecurved fatback trimming portion and sweeping radius portion are formedof different radii and are separated by a transition area.
 26. TheJ-blade of claim 22, wherein the generally straight blade section andthe sweeping radius portion are separated by a transition area.
 27. TheJ-blade apparatus of claim 19, wherein the cutoff portion is generallystraight.
 28. The J-blade apparatus of claim 19, and a cutoff angle bendformed between the sweeping radius portion and the cutoff portion. 29.The J-blade apparatus of claim 27, wherein the cutoff angle bend isformed of a radius no greater than approximately 0.390 inch.
 30. TheJ-blade apparatus of claim 19, wherein the cutting edge is formed as oneof a single bevel and a double bevel edge.
 31. The J-blade apparatus ofclaim 26, and a cutoff angle bend formed between the sweeping radiusportion and the cutoff portion, wherein the angle between the sweepingradius portion, relative to the cutoff portion, is formed within therange of approximately 83.9° and 88.5°.
 32. The J-blade apparatus ofclaim 26, and a cutoff angle bend formed between the sweeping radiusportion and the cutoff portion, wherein the cutoff angle bend is formedof a radius within the range from than approximately 0.1575 inch to0.2175 inch.
 33. The J-blade apparatus of claim 19, and a tab memberformed along the lower central portion and adapted to hold a diverterbar member for positioning a fatback strip cutoff during the loinpulling operation.
 34. The J-blade apparatus of claim 31, wherein thetab member is integrally formed with the blade member.
 35. The J-bladeapparatus of claim 31, wherein the tab member is positioned along thesweeping radius portion.
 36. The apparatus of claim 19, wherein theblade member has a substantially flawless mirror-like surface finish soas to minimize the side load forces created by blade member's cuttingdrag during operation.
 37. A method of forming an elongated andconfigured loin knife blade for use in a dual loin knife blade assemblyof a loin puller machine, comprising the steps of: milling the outerprofile for the knife blade; machining the knife blade's cutting edge;annealing the knife blade to soften the knife blade for forming;die-stamp forming the knife blade to form the needed angles, bends andedge profile; heat-treating the knife blade to a hardness betweenapproximately R.C. 44 to 54; and polishing the knife blade's surfaces tothereby minimize surface drag during meat cutting operations.
 38. Themethod of claim 35, and forming a Z-style blade.
 39. The method of claim35, and forming a J-style blade.
 40. The method of claim 37, and priorto the milling step, the step of one of laser-cutting and milling theprofile of the blade to include an integral tab portion, the tab adaptedto hold a diverter bar member.
 41. The method of claim 35, and beforethe polishing step, the step of quality control checking the profile ofthe knife blade to determine whether the heat treating step has changedthe knife blade's edge profile.
 42. The method step of claim 35, andwherein the polishing step comprises polishing the blade's surface to asurface finish with the range of approximately 4 to 32 microinches. 43.The method step 35, and wherein the annealing step comprises subjectingthe knife blade to a temperature range between approximately 1060° F. to1080° F., for approximately 85 to 95 minutes.
 44. The method of claim35, and the initial step of selecting, as the material for forming theblade, M2 steel.
 45. The method of claim 36, and when forming theZ-blade, the step of forming a lower blade portion, that normally is inengagement with the meat carcass during operation, to include a shelfblade portion having a length of approximately 2.7 inches.
 46. Themethod of claim 43, wherein the shelf blade portion comprises an upperfinger shelf portion, a shelf bend portion, and a lower loin avoidanceshelf portion.
 47. The method of claim 44, wherein the respective fingershelf portion and loin avoidance shelf portion are each formed assubstantially straight blade sections.